Organ stop switching circuit



June 17, 1952 v, l, ZUCK 2,601,218

ORGAN STOP SWITCHING CIRCUIT Filed May 20, 1949 FJ J3 IN V EN TOR.

Patented June 17, 1952 ORGAN STOP SWITCHING CIRCUIT Victor I. Zuck,Kenmore, N. Y., assignor to The Rudolph Wurlitzer Company, NorthTonawanda, N. Y., a corporation of Ohio Application May 20, 1949, SerialNo. 94,423

9 Claims. 1

This invention relates to electronic organs and more particularly to anelectronic organ stop switching means whereby the various tonegenerators may be selectively rendered effective.

The particular type of organ for which this switching system has beendevised utilizes a plurality of Wind driven vibrating metallic reeds astone generators. A plurality of pickup screws are threadedly mounted ina frame with their free ends spaced a short distance from the vibratingreed. The reeds and associated pickup screws form the plates of acapacitor as explained by Hoschke in his Patent Number 2,014,015 andwhen the reeds are vibrated as by an air blast the capacitance changesas a function of the vibration. When a potential is applied between thepickup screws and the reeds while the reeds are vibrating, analternating potential is produced between the reeds and the pickupscrews and may be amplied and translated into acoustic vibrations bymeans such as a loudspeaker. The reeds may be prevoiced by bending ortwisting to produce sounds similar to those produced by the variousstops of a pipe organ, as described by Hoschke in his aforementionedpatent. In the particular form of electronic organ in which thisswitching system is to be used, the depression of a single key opens apallet valve to admit air to actuate a plurality of tone generators asis described in detail in my copending application 719,896, filedJanuary 2, 1947, now U. S. Patent No. 2,570,178, granted October 2,1951. The physical arrangement of the keys, pallets, and tone generatorsis claimed in the copending application just noted.

It is an object of this invention to provide stop switching meanswherein certain of the tone generators actuated may be heard through theapplication of polarizing potential while others which are actuatedremain silent due to a lack of polarizing potential.

Another object of this invention is to provide stop switching meanswhereby the tonal scope of an electronic organ may be broad even thoughthe organ has but a single keyboard.

A further object is to provide stop switching means whereby a givengroup of tone generators serves to provide signal voltages for more thana single stop.

Other and further objects and advantages will be apparent from thefollowing description when taken with the accompanying drawing in which:

Fig. 1 is a fragmentary plan view of an electronic organ;

Fig. 2 is a fragmentary sectional view taken through the console of theinstrument showing the components that select and generate the organtones; and

Fig. 3 is a schematic electric wiring diagram of the switching andfiltering system, which comprises the most important part of thisinvention.

Referring now in greater particularity to the figures, the console I ofan electronic organ having a single manual is shown in Figs. 1 and 2. Aseries of keys 2 actuate the tone generators by means to be describedshortly in greater particularity and a series of stop tablets 3 areprovided, each of which actuates one of the switches illustrated in Fig.3. The keys are pivotally mounted on a frame 5 by means of pins l.Immediately above the rear extremities of the keys is a wind chest 9within which are disposed three banks of vibratory prevoiced reeds, thediapason reeds II being mounted horizontally, the ute reeds I3vertically, and the viole reeds I5, semi-vertically. Mounted adjacenteach bank of reeds are a plurality of banks of pickup screws I1, I9 and2I respectively, corresponding to the three banks of vibrating reeds.Although only one screw is shown associated with each reed, it iscontemplated that several screws might be used as taught by Hoschke inthe previously mentioned patent. Each bank of screws is electricallyconnected in parallel as is diagram matically illustrated in Fig. 3, andis connected to the input of an amplifier which is not shown`Immediately below the diapason reeds is a bank of pallet valves 22 whichare pivotally mounted on pins 23 and normally held in closed position bysprings 25. A coupler pin 21 serves as a coupling medium between eachkey l and its corresponding pallet valve 2|. The rear end of each key isslotted at 29 and a set screw 3I may adjust the width of the slot sothat there will'be no play between the key and the pin. Upon depressinga key 2, the corresponding pallet valve 2l is opened allowing a volumeof air to pass over each of the reeds corresponding to that valvethrough a compartment 33 and an aperture 35 to a wind return trunk 3l.An air compressor which may be of any suitable type is located withinthe organ housing or console I to provide the required air pressure, butis not shown.

The switching circuit which constitutes an important part of thisinvention is illustrated in Fig. 3. Polarizing potential is applied tothe parallel banks of reeds II, I3 and I5 by means of this switchingcircuit. The nute reeds are connected in but one parallel treble bank.The diapason and viole reeds, however, are each connected in two banks,bass and treble. A voltage divider 39 is connected across a source ofdirect current voltage to provide energizing potential for the reeds.Various taps on the voltage divider 39 are selectively connected to aseries of single pole double throw switches SW! through SWS, the firstfour of these switches being bass, corresponding to the viole anddiapason bass reeds, and the last iive being treble corresponding to thethree banks of treble reeds. Connection between the various switches andcorresponding reed banks is made through a B+ filter 3S comprising aresistance-capacitance network to lter out transient disturbancesarising from operation of the switches. Two groups of series connectedresistors RI through R13 and R14 through RIB also contribute to thereduction of transients and provide circuit isolation.

As an example of the switch connection, the bass diapason stop switch SWl is shown in its energized position to the right. This completes acircuit from the source of potential through a conductor 4I, seriesresistor Rl, switch SVH, conductor 3, switch SW2, series resistor R2,conductor 45, the B+ iilter and series resistor Rill to the bassdiapason reeds. Upon depression of one of the keys in the first twooctaves :z-

of the manual, the diapason and viole reeds corresponding to that keywill vibrate as air is admitted past the corresponding pallet valve. Asthe diapason reeds are energized, there will be an output therefrom tothe amplifier, but as the Viole reeds are not energized, the vibratingviole reed will not have any output. Ir" it is desired to operate thebass diapason reeds at a lowei` output level, this may be done by movingthe dulciana bass switch SW2 tc the right by means of one of the stoptablets This completes a circuit from a lower potential on the voltagedivider 35 through a conductor li?, resistor R3, switch SW2, and fromthere through the path previously described, comprising the resistor R2,conductor 45, the B+ lter and resistor R14 to the bass diapason reeds.As the potential applied in this manner to these reeds is lower thanthat applied previously, a smaller alternating current potential will beon the pickup screws and the output level will be less. If a ullcomplement of diapason tones is desired, the switch SW?, may be thrownto the right by one of the stop tablets 3 to energize the diapasonreeds. If it is desired to have a lower output level from the diapasontreble reeds, the dulciana switch SWE may be thrown to the right byanother one of the stop tablets 3 to connect a lower voltage to thereeds in a manner similar to that described with regard to the bassdiapason tablets. It is possible by selective operation of the switchesSW i through SWS by means of the stop tablets 3 to select any desirablecombination of bass and treble stops to obtain a wide range of tonalstructure with but a single manual. It is to be noted that upon openingany stop the corresponding reeds are immediately grounded to precludeany possibility of tonal overhang due to slow potential discharge fromthe capacitors in the B+ iilters. A tremulant which is not shown may becontrolled by one of the stop tablets so that ten stop tablets 3 areshown in Fig. l although there are only nine corresponding switches inFig. 3.

It is `apparent that I have herein provided an electronic organ having asingle manual having a plurality of groups of tone generators comprisingwind driven vibratory reeds. It is further apparent that the switchingcircuit presented makes it possible to selectively operate any desirablecombination of groups of reeds although a reed from every group isvibrated upon depression of one of the keys in the manual.

Although for illustrative purposes I have shown and described aparticular embodiment of my invention, it is to be understood that I donot intend to be limited thereby but only by the spirit and scope of theappended claims.

I claim:

l. In an electronic organ of the type having a plurality of wind drivenreeds as tone generators, said reeds arranged in a plurality of banks,electrical cooperative generator means adjacent each oi said reeds andarranged in banks, a manual, a plurality of keys in said manual, meansfor admitting an air blast simultaneously to a plurality of reeds indiierent banks in response to manipulation of one of said keys, a sourceof electrical potential, and means includswitching means for selectivelyapplying electrical potential to selected ones of said banks of reedsand associated cooperative generator means to provide a variable outputto an electronic amplifier, whereby a plurality of tonal outputs may beproduced from but a single manual.

In an electronic organ of the type having a plurality of wind drivenreeds as tone generators, said reeds arranged in a plurality of banks,electrical cooperative generator means adjacent each of said reeds andarranged in banks, a manual, a plurality of valves each for selectivelyadmitting an air blast simultaneously to a plurality of reeds indifferent banks, a plurality oi' keys in said manual, means linking saidkeys and said valves for rendering each valve operable in response to akey, a source o electric potential, and means including switch means forselectively applying electric potential to selected ones ci said banksof reeds and associated cooperative generator means to provide avariable electrical output from some or all of the reeds actuated by theair blast and the cooperative generator means associated therewith,whereby a plurality of tonal outputs may be produced from but a singlemanual.

3. In an electronic organ, a plurality of wind driven vibrating reeds,said reeds arranged in groups corresponding to organ stops, electricalcooperative generator `means associated with each of said reeds andarranged in groups, each reed and associated cooperative generator meansforming a variable electric capacitor, a manual, a plurality of keys insaid manual, means for admitting an air blast simultaneously tocorresponding reeds in a plurality of said groups in response tomovement of a single key, a source of a plurality of diierent volta-ges,and means including a plurality of stop switches selectivelyinterconnecting said voltage source and a group of the capacitors formedby said vibrating reeds and associated cooperative generator means forselectively applying voltages to selected ones of said groups of reedsand associated cooperative generator means to produce outputs from adesired number of the reeds vibrated by said air blast, whereby aplurality of tonal outputs may be produced from but a single manual.

4. In an electronic organ as defined in claim 3, stop switches having anelement connected to ground to ground a reed to prevent tonal overhangwhen potential is removed from said reed and its associated cooperativegenerator means by actuating a switch.

5. In an electronic organ, a plurality of wind driven vibrating metallicreeds, said reeds arranged in groups corresponding to organ stops, thereeds of each of said groups electrically connected in parallel in bassand treble sub-groups, electrical cooperative generator means associatedwith each of said reeds and arranged in groups corresponding to thegroups of reeds, each reed and its associated cooperative generatormeans forming a variable electric capacitor, a manual, a plurality ofkeys in said manual, means for admitting an air blast to correspondingreeds in a plurality of said groups of reeds in response to movement ofa single key, a source of a plurality of different voltages, a pluralityof organ stops, and a plurality of Stop switches actuated by said organstops and selectively interconnecting said voltage source and a group ofsaid vibrating reeds and associated cooperative generator -means forselectively applying voltages to said reeds and cooperative generatormeans to produce variable electrical outputs from a desired number ofthe reeds vibrated by said air blast, whereby a plurality of tonalyoutputs may be produced from but a single manual.

6. In an electronic organ, a plurality of wind driven vibrating metallicreeds of different tonal outputs, said reeds physically arranged ingroups corresponding to organ stops, means electrically connecting thereeds in each of such groups according to the tonal output of saidreeds, electrical cooperative generator means associated with each ofsaid reeds and arranged in groups corresponding to the groups of reeds,each reed and its associated cooperative generator means forming avariable electric capacitor, a manual, a plu-rality of keys in saidmanual, means for admitting an air blast to corresponding reeds in allof said groups in response to movement of a single key, a plurality oforgan stop controls, a source of a plurality of diiferent voltages, anda plurality of stop switches actuated by said organ stop controls andinterconnecting said voltage source and a group of said vibrating reedsand associated cooperative generator means for selectively applyingvoltages to selected ones of said groups of reeds and cooperativegenerator means to render certain of the reeds vibrated by said airblast effective, whereby a plurality of tonal outputs may be producedfrom a single manual.

'7. In an electronic organ, a plurality of wind driven vibrating reeds,said reeds physically arranged in groups according to the quality oftheir tonal output, said reeds further `connected electrically inparallel according to their tonal output, electrical cooperativegenerator means associated with each of said reeds and arranged ingroups corresponding` to the groups of reeds, each reed and itsassociated cooperative generator means forming a variable electricalcapacitor, a manual, a plurality ci keys in said manual,

means for admitting an air blast to one reed of each physical group inresponse to movement of a single key, a plurality of organ stopcontrols, a source of a plurality of different voltages, and a pluralityof stop switches actuated by said organ stop controls, each of saidswitches connected to said voltage source and at least some of saidswitches connected in pairs to the electrically parallel reeds andassociated cooperative generator means whereby to render selectivegroups of reeds and cooperative generator means effective and controlthe output thereof, in order to produce a plurality of tonal outputsfrom but a single manual.

8. In an electronic organ as vdefined in claim '7, in which the firstswitch of a pair is connected through the second switch so that the rstswitch is rendered inoperative upon actuation of the Isecond. switch.

9. In an electronic organ of the type having a plurality of wind drivenlreeds as tone generators, said reeds arranged in a plurality of banks,electrical cooperative generator means vassociated with each of saidreeds and arranged in banks corresponding to the groups of reeds, amanual, a plurality of keys in said manual, 4means for admitting an airblast simultaneously to a plurality of reeds in different banks inresponse to manipulation of one of said keys, takeup means varying adimension of each of said keys to eliminate lost motion between saidkeys and said air blast admitting means, a source of electricalpotential, and means including switch means for selectively applyingelectric potential to selected ones of said banks of reeds andassociated cooperative generator means to provide a variable electricaloutput to an electronic amplier, whereby a plurality of tonal outputsmay be produced from but a single manual.

VICTOR I. ZUCK.

REFERENCES CITED The following references are of record in the iile ofthis patent:

UNITED STATES PATENTS Number Name Date 2,113,347 Ho'schke Apr. 5, 19382,300,609 Zuck Nov. 3, 1942 2,318,936 Fisher May 11, 1943

